Inorgaic particle-containing composition, transfer film comprising the same and plasma display panel production process

ABSTRACT

An inorganic particle-containing composition comprising:  
     (A) inorganic particles;  
     (B) a binder resin; and  
     (C) at least one plasticizer selected from the group consisting of compounds represented by the following formula (1): 
     R 1 O—R 2  m OOC—(CH 2  n COOR 3 —O m R 4   ( 1 ) 
     wherein R 1  and R 4 are the same or different alkyl groups having 1 to 30 carbon atoms or alkenyl groups, R 2  and R 3  are the same or different alkylene groups having 1 to 30 carbon atoms or alkenylene groups, m is an integer of 0 to 5, and n is an integer of 1 to 10, and compounds represented by the following formula (2):  
                 
 
     wherein R 5  is an alkyl group having 1 to 30 carbon atoms or alkenyl group.  
     A transfer film and a plasma display panel production process using the composition are also described.

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an inorganic particle-containingcomposition, a transfer film comprising the same and a plasma displaypanel production process.

[0002] In recent years, much attention has been paid to a plasma displayas a plate-like fluorescent display. FIG. 1 is a diagram typicallyshowing the section of an AC plasma display panel (to be abbreviated as“PDP”hereinafter). In FIG. 1, reference numerals 1 and 2 denote glasssubstrates which are opposed to each other, and 3 a barrier. Cells areformed by the glass substrate 1, the glass substrate 2 and the barrier3. Denoted by 4 is a transparent electrode fixed on the glass substrate1, 5 a bus electrode formed on the transparent electrode 4 to reduce theresistance of the transparent electrode 4, 6 an address electrode fixedon the glass substrate 2, 7 a fluorescent material held in each cell, 8a dielectric layer formed on the surface of the glass substrate 1 tocover the transparent electrode 4 and the bus electrode 5, 9 adielectric layer formed on the surface of the glass substrate 2 to coverthe address electrode 6, and P a protective film made from magnesiumoxide, for example.

[0003] A color filter (red, green or blue) or a black matrix may beformed between the glass substrate and the dielectric layer to obtain ahigh-contract image in a color PDP.

[0004] There is known a method of forming the dielectric layer 8 whichcomprises preparing a pasty inorganic particle-containing composition(glass paste composition) containing glass powders, a binder resin and asolvent, coating the glass paste composition on the surface of the glasssubstrate 1 by a screen printing method, drying it to form a filmforming material layer, and baking this film forming material layer toremove the organic substances and sinter the glass powders.

[0005] As the binder resin forming the glass paste composition, thereare known cellulose derivatives such as methyl cellulose, ethylcellulose and carboxymethyl cellulose, polyvinyl alcohol's, polyvinylbutyral, urethane-based resins and melamine-based resins. Out of these,ethyl cellulose is preferred from the viewpoints of the dispersibilityof glass powders, the coating properties of the composition andflammability (refer to JP-A 6-321619) (the term “JP-A” as used hereinmeans an “unexamined published Japanese patent application”).

[0006] The thickness of the film forming material layer formed on theglass substrate 1 must be 1.3 to 2.0 times the thickness of thedielectric layer 8 to be formed in consideration of a reduction in thethickness of the film caused by the removal of the organic substances inthe baking step. For example, to adjust the thickness of the dielectriclayer 8 to 20 to 50 μm, a film forming material layer having a thicknessof 30 to 100 μm must be formed.

[0007] When the glass paste composition is coated by a screen printingmethod, the thickness of the coating film formed by a single time ofcoating is about 15 to 25 μm. Therefore, to form the film formingmaterial layer having a predetermined thickness, the glass pastecomposition must be coated on the surface of the glass substrate aplurality of times, for example, 2 to 7 times (multiple printing).

[0008] However, when the film forming material layer is formed bymultiple printing making use of the screen printing method, thedielectric layer formed by baking the film forming material layer doesnot have uniform thickness (for example, a tolerance of ±5% or less).This is because it is difficult to coat the glass paste compositionuniformly on the surface of the glass substrate by multiple printingmaking use of the screen printing method. As the coating area (panelsize) and the number of times of coating increase, nonuniformity in thethickness of the dielectric layer becomes larger. A panel material(glass substrate having the dielectric layer) obtained by the step ofcoating by multiple printing has nonuniform dielectric characteristicscaused by thickness nonuniformity within the plane and nonuniformdielectric characteristics cause surface defects (brightnessnonuniformity) in a PDP.

[0009] Further, the mesh form of a screen plate may be transferred tothe surface of the film forming material layer in the screen printingmethod and a dielectric layer formed by baking this film formingmaterial layer is inferior in surface flatness.

[0010] As means of solving the above problems when the film formingmaterial layer is formed by the screen printing method, the inventors ofthe present invention have proposed a PDP production process comprisingthe steps of coating a glass paste composition on the surface of a basefilm, drying the coating film to form a film forming material layer,transferring the film forming material layer formed on the base film tothe surface of a glass substrate having electrodes fixed thereon andbaking the transferred film forming material layer to form a dielectriclayer on the surface of the glass substrate (may be referred to as “dryfilm method” hereinafter)(refer to JP-A 9-102273).

[0011] According to this production process, a dielectric layer havingexcellent thickness uniformity and surface uniformity can be formed.

[0012] The present inventors have also proposed a composite filmcomprising a base film, a film forming material layer obtained from aglass paste composition and a cover film which is formed on the surfaceof the film forming material layer and can be peeled off easily as atransfer film which can be suitably used for the formation of thedielectric layer of a PDP (refer to JP-A 9-101653).

[0013] This composite film (transfer film) is advantageous because itcan be kept in the form of a roll.

[0014] The present inventors have further proposed a method of forming abarrier, electrode, resistor, dielectric layer, phosphor, color filterand black matrix which are the constituent elements of a PDP, whichcomprises the steps of coating a pasty inorganic particle-containingcomposition on the surface of a base film to form a film formingmaterial layer (transfer film), transferring the film forming materiallayer formed on the base film to the surface of a substrate, forming aresist film on the transferred film forming material layer, exposing theresist film to form a resist pattern latent image, developing the resistfilm to form a resist pattern, etching the film forming material layerto form a pattern layer corresponding to the resist pattern and bakingthe pattern layer (refer to JP-A 9-340514).

[0015] However, when the film forming material layer is formed bycoating a glass paste composition (inorganic particle-containingcomposition) containing a conventionally known resin such as a cellulosederivative on the surface of a base film (a transfer film is produced),the formed film forming material layer is not so flexible that thesurface of the film forming material layer is finely cracked if thetransfer film is bent.

[0016] A transfer film comprising a film forming material layer withunsatisfactory flexibility is inferior in suppleness and is difficult tobe rolled.

[0017] Since the film forming material layer containing a cellulosederivative cannot exhibit sufficient adhesion (thermal adhesion) to theglass substrate, it is difficult to transfer the layer from the basefilm to the surface of the glass substrate.

[0018] To cope with these problems, the present inventors have foundthat a transfer film having excellent transferability of the filmforming material layer (adhesion to the glass substrate) can be obtainedby preparing a glass paste composition containing an acrylic resin as abinder resin and coating the glass paste composition on the surface of abase film.

[0019] However, the film forming material layer formed by coating theglass paste composition containing an acrylic resin on the surface ofthe base film still does not have sufficient flexibility.

[0020] As means of providing flexibility to the film forming materiallayer constituting a transfer film, there is conceivable a method offorming a film forming material layer by preparing a glass pastecomposition containing an acrylic resin having high flexibility andcoating the glass paste composition on the surface of a base film.

[0021] However, the acrylic resin having high flexibility may not becompletely decomposed and removed in the step of baking the film formingmaterial layer and part of the acrylic resin may remain in the formedsintered body (for example, a dielectric layer composed of a glasssintered body) and color the dielectric layer, thereby impairing itslight transmission properties.

[0022] The present invention has been made under the abovecircumstances.

[0023] It is a first object of the present invention to provide aninorganic particle-containing composition capable of forming aconstituent element (for example, a barrier, electrode, resistor,dielectric layer, phosphor, color filter or black matrix) of a PDPadvantageously.

[0024] It is a second object of the present invention to provide aninorganic particle-containing composition capable of forming a glasssintered body (for example, a dielectric layer constituting a PDP)having high light transmittance.

[0025] It is a third object of the present invention to provide aninorganic particle-containing composition capable of producing atransfer film comprising a film forming material layer having excellentflexibility.

[0026] It is a fourth object of the present invention to provide aninorganic particle-containing composition capable of producing atransfer film having excellent transferability, that is, heat adhesionof a film forming material layer to a substrate.

[0027] It is a fifth object of the present invention to provide atransfer film capable of forming a constituent element of a PDPefficiently.

[0028] It is a sixth object of the present invention to provide atransfer film comprising a film forming material layer having excellentflexibility.

[0029] It is a seventh object of the present invention to provide atransfer film having excellent transferability (heat adhesion to asubstrate) of a film forming material layer.

[0030] It is an eighth object of the present invention to provide a PDPproduction process capable of forming a constituent element of a PDPefficiently.

[0031] It is a ninth object of the present invention to provide a PDPproduction process capable of forming a PDP having the high positionaccuracy of a constituent element.

[0032] It is a tenth object of the present invention to provide a PDPproduction process capable of forming a dielectric layer having largethickness efficiently.

[0033] It is an eleventh object of the present invention to provide aPDP production process capable of forming a dielectric layer requiredfor a large panel efficiently.

[0034] It is a twelfth object of the present invention to provide aprocess for producing a PDP having a dielectric layer with excellentthickness uniformity.

[0035] It is a thirteenth object of the present invention to provide aprocess for producing a PDP having a dielectric layer with excellentsurface flatness.

[0036] Other objects and advantages of the present invention will becomeapparent from the following description.

[0037] According to the present invention, firstly, the above objectsand advantages of the present invention are attained by an inorganicparticle-containing composition comprising:

[0038] (A) inorganic particles;

[0039] (B) a binder resin; and

[0040] (C) at least one plasticizer selected from the group consistingof compounds represented by the following formula (1):

R¹O-R²_(m)OOC—(CH₂_(n)COOR³-O_(m)R⁴  (1)

[0041] wherein R¹ and R⁴are the same or different alkyl groups having 1to 30 carbon atoms or alkenyl groups, R⁴ and R³ are the same ordifferent alkylene groups having 1 to 30 carbon atoms or alkenylenegroups, m is an integer of 0 to 5, and n is an integer of 1 to 10, andcompounds represented by the following formula (2):

[0042] wherein R⁵ is an alkyl group having 1 to 30 carbon atoms oralkenyl group.

[0043] Secondly, the above objects and advantages of the presentinvention are attained by a transfer film comprising a film formingmaterial layer formed of the above inorganic particle-containingcomposition.

[0044] Thirdly, the above objects and advantages of the presentinvention are attained by a PDP production process which comprises thesteps of transferring a film forming material layer constituting theabove transfer film to the surface of a substrate and baking thetransferred film forming material layer to form a dielectric layer onthe substrate.

[0045] Fourthly, the above objects and advantages of the presentinvention are attained by a PDP production process which comprises thesteps of transferring a film forming material layer formed of the aboveinorganic particle-containing composition to the surface of a substrate,forming a resist film on the transferred film forming material layer,exposing the resist film to form a resist pattern latent image,developing the resist film to form a resist pattern, etching the filmforming material layer to form a pattern layer corresponding to theresist pattern, and baking the pattern layer to form a constituentelement selected from the group consisting of a barrier, electrode,resistor, dielectric layer, phosphor, color filter and black matrix.

[0046] Fifthly, the above objects and advantages of the presentinvention are attained by a PDP production process which comprises thesteps of forming a laminate film consisting of a resist film and a filmforming material layer formed of the above inorganic particle-containingcomposition on a base film in the order named, transferring the laminatefilm formed on the base film to the surface of a substrate, exposing theresist film constituting the laminate film to form a resist patternlatent image, developing the resist film to form a resist pattern,etching the film forming material layer to form a pattern layercorresponding to the resist pattern, and baking the pattern layer toform a constituent element selected from the group consisting of abarrier, electrode, resistor, dielectric layer, phosphor, color filterand black matrix.

BRIEF DESCRIPTION OF THE DRAWINGS

[0047]FIG. 1 is a diagram typically showing the section of an AC plasmadisplay panel;

[0048]FIG. 2(a) is a schematic sectional view of a transfer film of thepresent invention and FIG. 2(b) is a sectional view showing the layerstructure of the transfer film;

[0049] FIGS. 3 are schematic sectional views showing an example of abarrier forming process (transfer step, resist film forming step andexposure step) in the production process of the present invention; and

[0050] FIGS. 4 are schematic sectional views showing an example of abarrier forming process (developing step, etching step and baking step)in the production process of the present invention.

[0051] The inorganic particle-containing composition of the presentinvention will be described in detail hereinunder.

[0052] The composition of the present invention comprises inorganicparticles, a binder resin and a plasticizer represented by a specificstructural formula as essential ingredients.

Inorganic Particles

[0053] An inorganic material forming the inorganic particlesconstituting the composition of the present invention is notparticularly limited and an appropriate inorganic material is selectedaccording to the application purpose of a sintered body formed of thecomposition (type of constituent element of a PDP).

[0054] The inorganic particles contained in the composition for forminga “dielectric layer”or “barrier” constituting a PDP are, for example,glass powders having a softening point of 400 to 600° C.

[0055] When the softening point of the glass powders is lower than 400°C., part of organic substances such as a binder resin remain in theformed dielectric layer because glass powders are molten when theorganic substances are not completely decomposed and removed in the stepof baking the film forming material layer of the above composition,whereby the dielectric layer is apt to be colored and its lighttransmittance tends to lower. When the softening point of the glasspowders is higher than 600° C., a glass substrate is readily distortedbecause the glass powders must be baked at a temperature higher than600° C.

[0056] Preferred examples of the glass powders include (1) a mixture oflead oxide, boron oxide and silicon oxide (PbO—B₂O₃—SiO₂), (2) a mixtureof zinc oxide, boron oxide and silicon oxide (ZnO—B₂O₃—SiO₂), (3) amixture of lead oxide, boron oxide, silicon oxide and aluminum oxide(PbO—B₂O₃—SiO₂—Al₂O₃), and (4) a mixture of lead oxide, zinc oxide,boron oxide and silicon oxide (PbO—ZnO—B₂O₃—SiO₂), and the like.

[0057] These glass powders may be contained in the composition forforming a constituent element (for example, an electrode, resistor,phosphor, color filter or black matrix) other than the dielectric layerand the barrier.

[0058] The inorganic particles contained in a composition for forming an“electrode” constituting a PDP are preferably Ag, Au, Al, Ni, Ag—Pdalloy, Cu or Cr particles.

[0059] The inorganic particles contained in a composition for forming a“resistor” constituting a PDP are RuO₂ particles or the like.

[0060] The inorganic particles contained in a composition for forming a“phosphor” constituting a PDP are a red fluorescent material such asY₂O₃:Eu³⁺, Y₂SiO₅:Eu³⁺, Y₃Al₅O₁₂:Eu³⁺, YVO₄:EU³⁺, (Y, Gd) BO₃: Eu³⁺orZn₃(PO₄)₂:Mn; green fluorescent material such as Zn₂SiO₄:Mn,BaAl₁₂O₁₉:Mn, BaMgAl₁₄O₂₃:Mn, LaPO₄:(Ce,Tb) or Y₃(Al,Ga)₅O₁₂:Tb; or bluefluorescent material such as Y₂SiO₅: Ce, BaMgAl₁₀O₁₇,:Eu²⁺,BaMgAl₁₄O₂₃:Eu²⁺, (Ca,Sr,Ba)₁₀(PO₄)₆Cl₂:Eu²⁺ or (Zn,Cd)S:Ag.

[0061] The inorganic particles contained in a composition for forming a“color filter” constituting a PDP are a red material such as Fe₂O₃ orPb₃O₄, green material such as Cr₂O₃, or blue material such as2(Al₂Na₂Si₃O₁₀) Na₂S₄.

[0062] The inorganic particles contained in a composition for forming a“black matrix” constituting a PDP are Mn, Fe or Cr particles.

Binder Resin

[0063] The binder resin constituting the composition of the presentinvention is preferably an acrylic resin. Since the composition containsan acrylic resin as the binder resin, the formed film forming materiallayer exhibits excellent (heat) adhesion to a substrate. Therefore, whenthe composition of the present invention is coated on the surface of abase film to form a transfer film, the obtained transfer film hasexcellent transferability, that is, heat adhesion of the film formingmaterial layer to the substrate.

[0064] As the acrylic resin constituting the composition of the presentinvention is used a (co)polymer which has appropriate tackiness, canbind inorganic particles and is completely oxidized and removed by thebaking of the film forming material (at 400 to 600° C.).

[0065] The acrylic resin preferably contains a polymer unit derived froma (meth)acrylate compound represented by the following general formula(3):

[0066] wherein R⁶ is a hydrogen atom or methyl group, and R⁷ is amonovalent organic group.

[0067] The acrylic resin is, for example, a homopolymer of a(meth)acrylate compound represented by the above formula (3), acopolymer of two or more (meth)acrylate compounds represented by theabove formula (3) or a copolymer of a (meth)acrylate compoundrepresented by the above formula (3) and other copolymerizable monomer.

[0068] Illustrative examples of the (meth)acrylate compound representedby the above formula (3) include alkyl (meth)acrylates such as methyl(meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl(meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl(meth)acrylate, pentyl (meth)acrylate, amyl (meth)acrylate, isoamyl(meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl(meth)acrylate, isooctyl (meth)acrylate, ethylhexyl (meth)acrylate,nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate,undecyl (meth)acrylate, dodecyl (meth)acrylate, lauryl (meth)acrylate,stearyl (meth)acrylate and isostearyl (meth)acrylate; hydroxyalkyl(meth)acrylates such as hydroxyethyl (meth)acrylate, 2-hydroxypropyl(meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl(meth)acrylate, 3-hydroxybutyl (meth)acrylate and 4-hydroxybutyl(meth)acrylate; phenoxyalkyl (meth)acrylates such as phenoxyethyl(meth)acrylate and 2-hydroxy-3-phenoxypropyl (meth)acrylate; alkoxyalkyl(meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl(meth)acrylate, 2-propoxyethyl (meth)acrylate, 2-butoxyethyl(meth)acrylate and 2-methoxybutyl (meth)acrylate; polyalkylene glycol(meth)acrylates such as polyethylene glycol mono(meth)acrylate,ethoxydiethylene glycol (meth)acrylate, methoxypolyethylene glycol(meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, polypropylene glycolmono(meth)acrylate, methoxypolypropylene glycol (meth)acrylate,ethoxypolypropylene glycol (meth)acrylate and nonyl phenoxypolypropyleneglycol (meth)acrylate; cycloalkyl (meth)acrylates such as cyclohexyl(meth)acrylate, 4-butylcyclohexyl (meth)acrylate, dicyclopentanyl(meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentadienyl(meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate andtricyclodecanyl (meth)acrylate; benzyl (meth)acrylate,tetrahydrofurfuryl (meth)acrylate and the like.

[0069] Out of these, (meth)acrylate compounds of the formula (3) inwhich the group represented by R⁷ contains an alkyl group or oxyalkylenegroup are preferred. Particularly preferred (meth)acrylate compounds arebutyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate,isodecyl (meth)acrylate and 2-ethoxyethyl (meth)acrylate. The othercopolymerizable monomer is not particularly limited if it can becopolymerized with the above (meth)acrylate compounds, as exemplified byunsaturated carboxylic acids such as (meth)acrylic acid, vinylbenzoicacid, maleic acid and vinylphthalic acid; and vinyl group-containingradical polymerizable compounds such as vinylbenzyl methyl ether, vinylglycidyl ether, styrene, a-methylstyrene, butadiene and isoprene. Theproportion of the polymer unit derived from the (meth)acrylate compoundrepresented by the above formula (3) in the acrylic resin constitutingthe composition of the present invention is preferably 70 wt % or more,more preferably 90 wt % or more.

[0070] Preferred examples of the acrylic resin include polymethylmethacrylate, polybutyl methacrylate, methyl methacrylate-butylmethacrylate copolymer and the like.

[0071] When the film forming material needs to be alkali-soluble to beetched for the formation of a constituent element of a PDP using aphotoresist method which will be described hereinafter, an unsaturatedcarboxylic acid is preferably used as at least part of the above othercoplymerizable monomer (comonomer).

[0072] The weight average molecular weight in terms of styrene measuredby GPC (to be simply referred to as “weight average molecular weight”hereinafter) of the acrylic resin constituting the composition of thepresent invention is preferably 4,000 to 300,000, more preferably 10,000to 200,000.

[0073] The proportion of the binder resin in the composition of thepresent invention is preferably 5 to 80 parts by weight, more preferably10 to 50 parts by weight based on 100 parts by weight of the inorganicparticles. When the proportion of the binder resin is too small, thebinder resin cannot bind and hold the inorganic particles firmly andwhen the proportion is too large, the baking step may take long or theformed sintered body (for example, a dielectric layer) may not havesufficient strength or thickness.

Plasticizer

[0074] The composition of the present invention is characterized in thatit contains a plasticizer (to be referred to as “specific plasticizer”hereinafter) which is a compound represented by the following formula(1):

R¹O-R²_(m)OOC—(CH₂_(n)COOR³-O_(m)R⁴  (1)

[0075] wherein R¹ and R⁴ are the same or different alkyl groups having 1to 30 carbon atoms or alkenyl groups, R² and R³ are the same ordifferent alkylene groups having 1 to 30 carbon atoms or alkenylenegroups, m is an integer of 0 to 5, and n is an integer of 1 to 10, orthe following formula (2):

[0076] wherein R⁵ is an alkyl group having 1 to 30 carbon atoms oralkenyl group.

[0077] The composition of the present invention containing the specificplasticizer enables the formed film forming material layer to exhibitexcellent flexibility and flammability.

[0078] Therefore, even when the transfer film comprising the filmforming material layer containing the specific plasticizer is bent, thesurface of the film forming material layer is not finely cracked, andthe transfer film has excellent suppleness and can be rolled easily.

[0079] Moreover, as the specific plasticizer can be easily decomposed byheat and removed, it does not reduce the light transmittance of adielectric layer obtained by baking the film forming material layer.

[0080] In the above formula (1) representing the specific plasticizer,R¹ and R⁴ are the same or different alkyl groups having 1 to 30 carbonatoms or alkenyl groups, R² and R³ are the same or different alkylenegroups having 1 to 30 carbon atoms or alkenylene groups, m is an integerof 0 to 5, and n is an integer of 1 to 10. The alkyl group or alkenylgroup represented by R¹ or R⁴ and the alkylene group or alkenylene grouprepresented by R² or R³ may be straight-chain or branched.

[0081] The number of carbon atoms of the alkyl group represented by R¹or R⁴ is 1 to 30, preferably 2 to 20, more preferably 4 to 10.

[0082] When the number of carbon atoms of the alkyl group is more than30, the solubility in a solvent of the plasticizer constituting theinorganic particle-containing composition may lower and excellentflexibility may not be obtained.

[0083] In the above formula (1), n is an integer of 1 to 10.

[0084] Illustrative examples of the compound represented by the aboveformula (1) include dibutyl adipate, diisobutyl adipate, di-2-ethylhexyladipate, di-2-ethylhexyl azelate, dibutyl sebacate, dibutyl diglycoladipate and the like. Compounds of the formula (1) in which n is aninteger of 2 to 6 are preferred.

[0085] In the above formula (2) representing the specific plasticizer,R⁵ is an alkyl group having 1 to 30 carbon atoms or alkenyl group. Thealkyl group and alkenyl group may be straight-chain or branched.

[0086] The number of carbon atoms of the alkyl group or alkenyl grouprepresented by R⁵ is 1 to 30, preferably 2 to 20, more preferably 10 to18.

[0087] Illustrative examples of the compound represented by the aboveformula (2) include propylene glycol monolaurate, propylene glycolmonooleate and the like.

[0088] The proportion of the specific plasticizer in the composition ofthe present invention is preferably 0.1 to 20 parts by weight, morepreferably 0.5 to 10 parts by weight based on 100 parts by weight of theinorganic particles. When the proportion of the specific plasticizer istoo small, the plasticity of the film forming material layer formed ofthe obtained composition can hardly be improved satisfactorily. When theproportion is too large, the tackiness of the film forming materiallayer formed of the obtained composition becomes too high with theresult that a transfer film comprising the film forming material layeris inferior in handling properties.

Solvent

[0089] The composition of the present invention generally contains asolvent. The solvent preferably has excellent affinity for the inorganicparticles and excellent solubility of the binder resin, can provideappropriate viscosity to the obtained composition and can be easilyvaporized and removed by drying.

[0090] Illustrative examples of the solvent include ketones such asdiethyl ketone, methylbutyl ketone, dipropyl ketone and cyclohexanone;alcohol's such as n-pentanol, 4-methyl-2-pentanol, cyclohexanol anddiacetone alcohol; ether-based alcohol's such as ethylene glycolmonomethyl ether, ethylene glycol monoethyl ether, ethylene glycolmonobutyl ether, propylene glycol monomethyl ether and propylene glycolmonoethyl ether; saturated aliphatic alkyl monocarboxylates such asn-butyl acetate and amyl acetate; lactates such as ethyl lactate andn-butyl lactate; ether-based esters such as methyl cellosolve acetate,ethyl cellosolve acetate, propylene glycol monomethyl ether acetate andethyl-3-ethoxypropionate; and the like. These solvents may be used aloneor in combination of two or more.

[0091] The proportion of the solvent in the composition of the presentinvention is preferably 40 parts or less by weight, more preferably 5 to30 parts by weight based on 100 parts by weight of the inorganicparticles from the viewpoint of maintaining the viscosity of thecomposition at a preferred range.

Silane Coupling Agent

[0092] The composition of the present invention may contain a silanecoupling agent. The silane coupling agent is preferably an alkylgroup-containing (alkyl)alkoxysilane represented by the followingformula (4):

[0093] wherein p is an integer of 3 to 20, m is an integer of 1 to 3, nis an integer of 1 to 3, and a is an integer of 1 to 3.

[0094] In the above formula (4), p indicating the number of carbon atomsof an alkyl group is an integer of 3 to 20, preferably 4 to 16.

[0095] Even when an alkyl group-containing (alkyl)alkoxysilane of theformula (4) in which p is less than 3 is contained in the composition, afilm forming material layer formed of the obtained composition may nothave satisfactory flexibility. Since an alkyl group-containing(alkyl)alkoxysilane of the formula (4) in which p is more than 20 hashigh decomposition temperature, part of the organic substances mayremain in the formed dielectric layer when the above silane compound isnot completely decomposed and removed in the step of baking the filmforming material layer of the obtained composition, whereby the lighttransmittance of the dielectric layer may be reduced.

[0096] Illustrative examples of the silane coupling agent represented bythe above formula (4) include saturated alkyldimethyl methoxysilanes(a=1, m=1, n=1) such as n-propyldimethyl methoxysilane, n-butyldimethylmethoxysilane, n-decyldimethyl methoxysilane, n-hexadecyldimethylmethoxysilane and n-eicosanedimethyl methoxysilane; saturatedalkyldiethyl methoxysilanes (a=1, m=1, n=2) such as n-propyldiethylmethoxysilane, n-butyldiethylmethoxysilane, n-decyldiethylmethoxysilane,n-hexadecyldiethyl methoxysilane and n-eicosanediethyl methoxysilane;saturated alkyldipropyl methoxysilanes (a=1, m=1, n=3) such asn-butyldipropyl methoxysilane, n-decyldipropyl methoxysilane,n-hexadecyldipropyl methoxysilane and n-eicosanedipropyl methoxysilane;saturated alkyldimethyl ethoxysilanes (a=1, m=2, n=1) such asn-propyldimethyl ethoxysilane, n-butyldimethyl ethoxysilane,n-decyldimethyl ethoxysilane, n-hexadecyldimethyl ethoxysilane andn-eicosanedimethyl ethoxysilane; saturated alkyldiethyl ethoxysilanes(a=1, m=2, n=2) such as n-propyldiethyl ethoxysilane, n-butyldiethylethoxysilane, n-decyldiethyl ethoxysilane, n-hexadecyldiethylethoxysilane and n-eicosanediethyl ethoxysilane; saturated alkyldipropylethoxysilanes (a=1, m=2, n=3) such as n-butyldipropyl ethoxysilane,n-decyldipropyl ethoxysilane, n-hexadecyldipropyl ethoxysilane andn-eicosanedipropyl ethoxysilane; saturated alkyldimethyl propoxysilanes(a=1, m=3, n=1) such as n-propyldimethyl propoxysilane, n-butyldimethylpropoxysilane, n-decyldimethyl propoxysilane, n-hexadecyldimethylpropoxysilane and n-eicosanedimethyl propoxysilane; saturatedalkyldiethyl propoxysilanes (a=1, m=3, n=2) such as n-propyldiethylpropoxysilane, n-butyldiethyl propoxysilane, n-decyldiethylpropoxysilane, n-hexadecyldiethyl propoxysilane and n-eicosanediethylpropoxysilane; saturated alkyldipropyl propoxysilanes (a=1, m=3, n=3)such as n-butyldipropyl propoxysilane, n-decyldipropyl propoxysilane,n-hexadecyldipropyl propoxysilane and n-eicosanedipropyl propoxysilane;saturated alkylmethyl dimethoxysilanes (a=2, m=1, n=1) such asn-propylmethyl dimethoxysilane, n-butylmethyl dimethoxysilane,n-decylmethyl dimethoxysilane, n-hexadecylmethyl dimethoxysilane andn-eicosanemethyl dimethoxysilane; saturated alkylethyl dimethoxysilanes(a=2, m=1, n=2) such as n-propylethyl dimethoxysilane, n-butylethyldimethoxysilane, n-decylethyl dimethoxysilane, n-hexadecylethyldimethoxysilane and n-eicosaneethyl dimethoxysilane; saturatedalkylpropyl dimethoxysilanes (a=2, m=1, n=3) such as n-butylpropyldimethoxysilane, n-decylpropyl dimethoxysilane, n-hexadecylpropyldimethoxysilane and n-eicosanepropyl dimethoxysilane; saturatedalkylmethyl diethoxysilanes (a=2, m=2, n=1) such as n-propylmethyldiethoxysilane, n-butylmethyl diethoxysilane, n-decylmethyldiethoxysilane, n-hexadecylmethyl diethoxysilane and n-eicosanemethyldiethoxysilane; saturated alkylethyl diethoxysilanes (a=2, m=2, n=2)such as n-propylethyl diethoxysilane, n-butylethyl diethoxysilane,n-decylethyl diethoxysilane, n-hexadecylethyl diethoxysilane andn-eicosaneethyl diethoxysilane; saturated alkylpropyl diethoxysilanes(a=2, m=2, n=3) such as n-butylpropyl diethoxysilane, n-decylpropyldiethoxysilane, n-hexadecylpropyl diethoxysilane and n-eicosanepropyldiethoxysilane; saturated alkylmethyl dipropoxysilanes (a=2, m=3, n=1)such as n-propylmethyl dipropoxysilane, n-butylmethyl dipropoxysilane,n-decylmethyl dipropoxysilane, n-hexadecylmethyl dipropoxysilane andn-eicosanemethyl dipropoxysilane; saturated alkylethyl dipropoxysilanes(a=2, m=3, n=2) such as n-propylethyl dipropoxysilane, n-butylethyldipropoxysilane, n-decylethyl dipropoxysilane, n-hexadecylethyldipropoxysilane and n-eicosaneethyl dipropoxysilane; saturatedalkylpropyl dipropoxysilanes (a=2, m=3, n=3) such as n-butylpropyldipropoxysilane, n-decylpropyl dipropoxysilane, n-hexadecylpropyldipropoxysilane and n-eicosanepropyl dipropoxysilane; saturated alkyltrimethoxysilanes (a=3, m=1) such as n-propyl trimethoxysilane, n-butyltrimethoxysilane, n-decyl trimethoxysilane, n-hexadecyl trimethoxysilaneand n-eicosane trimethoxysilane; saturated alkyl triethoxysilanes (a=3,m=2) such as n-propyl triethoxysilane, n-butyl triethoxysilane, n-decyltriethoxysilane, n-hexadecyl triethoxysilane and n-eicosanetriethoxysilane; and saturated alkyl tripropoxysilanes (a=3, m=3) suchas n-propyl tripropoxysilane, n-butyl tripropoxysilane, n-decyltripropoxysilane, n-hexadecyl tripropoxysilane and n-eicosanetripropoxysilane. They may be used alone or in combination of two ormore.

[0097] Out of these, n-butyl trimethoxysilane, n-decyl trimethoxysilane,n-hexadecyl trimethoxysilane, n-decyldimethyl methoxysilane,n-hexadecyldimethyl methoxysilane, n-butyl triethoxysilane, n-decyltriethoxysilane, n-hexadecyl triethoxysilane, n-decylethyldiethoxysilane, n-hexadecylethyl diethoxysilane, n-butyltripropoxysilane, n-decyl tripropoxysilane and n-hexadecyltripropoxysilane are particularly preferred.

[0098] The proportion of the silane coupling agent in the composition ofthe present invention is preferably 0.001 to 10 parts by weight, morepreferably 0.001 to 5 parts by weight based on 100 parts by weight ofthe inorganic particles. When the proportion of the silane couplingagent is too small, the effect of improving the dispersion stability ofthe inorganic particles and the effect of improving the flexibility ofthe formed film forming material layer can hardly be developed in full.When the proportion is too large, the viscosity of the obtainedcomposition may rise with the passage of time when it is preserved, or areaction may occur between the silane coupling agents, thereby reducinglight transmittance after baking.

[0099] The composition of the present invention may contain suchadditives as a dispersant, tackiness providing agent, surface tensioncontrol agent, stabilizer, antifoaming agent and the like as optionalcomponents, in addition to the above components.

[0100] The composition of the present invention can be prepared bykneading the above inorganic particles, binder resin, specificplasticizer, solvent and optional components with a kneader such as aroll kneader, mixer or homomixer.

[0101] The composition of the present invention prepared as describedabove is a pasty composition having fluidity suitable for coating. Theviscosity of the composition of the present invention is preferably1,000 to 30,000 cp, more preferably 3,000 to 10,000 cp.

[0102] The composition of the present invention can be particularlyadvantageously used to produce the transfer film of the presentinvention which will be detailed hereinunder.

[0103] The composition of the present invention can be advantageouslyused in a conventionally known method of forming a film forming materiallayer, that is, a method of forming a film forming material layer bydirectly coating the composition on the surface of a substrate by ascreen printing method and drying the coating film.

Transfer Film

[0104] The transfer film of the present invention is a composite filmwhich is advantageously used in the step of forming a constituentelement of a PDP, particularly the step of forming a dielectric layerand comprises a film forming material layer formed by coating thecomposition of the present invention on the surface of a base film anddrying the coating film. That is, the transfer film of the presentinvention comprises a base film and a film forming material layercontaining inorganic particles, a binder resin and a specificplasticizer and formed on the base film.

[0105] The transfer film of the present invention may be a laminate filmobtained by forming a resist film which will be described hereinafter ona base film, coating the composition of the present invention on theresist film and drying the coating film.

[0106] (1) Constitution of Transfer Film

[0107]FIG. 2(a) is a schematic sectional view of the rolled transferfilm of the present invention and FIG. 2(b) is a sectional view showingthe layer structure of the transfer film [detail view of a portion (X)].

[0108] The transfer film shown in FIG. 2 is a composite film used toform a dielectric layer constituting a PDP as an example of the transferfilm of the present invention. The transfer film generally comprises abase film F1, a film forming material layer F2 which is formed on thesurface of the base film F1 and can be peeled off, and a cover film F3which is formed on the surface of the film forming material layer F2 andcan be peeled off. The cover film F3 may not be used according to theproperties of the film forming material layer F2.

[0109] The base film F1 constituting the transfer film is preferably aresin film having heat resistance, solvent resistance and flexibility.When the base film F1 has flexibility, the pasty composition of thepresent invention can be coated by a roll coater or blade coater,thereby making it possible to form a film forming material layer havinguniform thickness and to keep and supply the formed film formingmaterial layer in the form of a roll.

[0110] A resin forming the base film F1 is, for example, polyethyleneterephthalate, polyester, polyethylene, polypropylene, polystyrene,polyimide, polyvinyl alcohol, polyvinyl chloride, fluororesin such aspolyfluoroethylene, nylon or cellulose. The base film F1 has a thicknessof 20 to 100 μm, for example.

[0111] The film forming material layer F2 constituting the transfer filmis a layer which turns into a glass sintered body (dielectric layer) bybaking and contains glass powders (inorganic particles), a binder resinand a specific plasticizer as essential ingredients.

[0112] The thickness of the film forming material layer F2, whichdiffers according to the content of the glass powders and the type andsize of a panel, is 5 to 200 μm, preferably 10 to 100 μm. When thethickness is smaller than 5 μm, the thickness of the finally formeddielectric layer becomes too small and desired dielectriccharacteristics may not be ensured. When this thickness is in the rangeof 10 to 100 μm, the thickness of the dielectric layer required for alarge-sized panel can be ensured.

[0113] The cover film F3 constituting the transfer film is a film forprotecting the surface of the film forming material layer F2 (contactsurface with the glass substrate). This cover film F3 is preferably aresin film having flexibility. Illustrative examples of the resinforming the cover film F3 are the same as those listed for the base filmF1. The thickness of the cover film F3 is 20 to 100 μm, for example.

[0114] (2) Transfer Film Production Process

[0115] The transfer film of the present invention can be produced byforming the film forming material layer F2 on the base film F1 andforming the cover film F3 on the film forming material layer F3 (pressbonding).

[0116] To form the film forming material layer, the composition of thepresent invention containing inorganic particles, a binder resin, aspecific plasticizer and a solvent is coated on the surface of a basefilm and the coating film is dried to remove part or all of the solvent.

[0117] To coat the composition of the present invention on the surfaceof the base film, a roll coater, blade coater such as a doctor blade,curtain coater, wire coater or the like is preferably used because acoating film having excellent thickness uniformity can be efficientlyformed.

[0118] The surface of the base film coated with the composition of thepresent invention is preferably subjected to a release treatment.Thereby, the base film can be easily peeled of f from the film formingmaterial layer after the film forming material layer is transferred.

[0119] The coating film of the composition of the present inventionformed on the base film is dried to remove part or all of the solventand turns into a film forming material layer constituting the transferfilm. Conditions for drying the coating film of the composition of thepresent invention include a temperature of 40 to 150° C. and a time ofabout 0.1 to 30 minutes. The content of the solvent after drying, thatis, the content of the solvent in the film forming material layer ispreferably 10 wt % or less, more preferably 1 to 5 wt % so as to causethe film forming material layer to exhibit tackiness to the substrateand appropriate shape retention properties.

[0120] The surface of the cover film formed on the film forming materiallayer formed as described above (generally press-bonded under heating)is preferably subjected to a release treatment as well. Thereby, thecover film can be easily peeled off from the film forming material layerbefore the film forming material layer is transferred.

[0121] (3) Transfer of Film Forming Material Layer (Usage of TransferFilm)

[0122] The film forming material layer formed on the base film istransferred to the surface of the substrate en bloc. Since the transferfilm of the present invention enables the film forming material layer tobe formed on the glass substrate by the above simple operation withoutfail, the efficiency of the step of forming a constituent element of aPDP such as a dielectric layer can be improved and the improvement ofthe quality of the formed constituent element, for example, thedevelopment of stable dielectric characteristics in the dielectric layercan be realized.

PDP Production Process (Formation of Dielectric Layer)

[0123] The production process of the present invention comprises thesteps of transferring a film forming material layer constituting thetransfer film of the present invention to the surface of a substrate andbaking the transferred film forming material layer to form a dielectriclayer on the surface of the substrate.

[0124] An example of the step of transferring the film forming materiallayer of the transfer film constituted as shown in FIGS. 2 is asfollows.

[0125] (1) The transfer film in the form of a roll is cut to a sizecorresponding to the area of the substrate.

[0126] (2) After the cover film F3 is peeled off from the surface of thefilm forming material layer F2 of the cut transfer film, the transferfilm is placed upon the surface of the substrate in such a manner thatthe surface of the film forming material layer F2 comes into contactwith the substrate.

[0127] (3) A heating roll is moved over the transfer film placed uponthe substrate to press bond the transfer film under heating.

[0128] (4) The base film F1 is peeled off and removed from the filmforming material layer F2 press-bonded to the substrate under heating.

[0129] The film forming material layer F2 formed on the base film F1 istransferred to the surface of the substrate by the above operation.Transfer conditions include a heating roll surface temperature of 60 to120° C., a heating roll pressure of 1 to 5 kg/cm², and a heating rollmoving speed of 0.2 to 10.0 m/min. This operation (transfer step) can becarried out with a laminator. The substrate may be preheated at atemperature of 40 to 100° C., for example.

[0130] The film forming material layer F2 transferred to the surface ofthe substrate turns into an inorganic sintered body (dielectric layer)by baking. Baking is carried out by placing the substrate having thefilm forming material layer F2 transferred thereto in a high-temperatureatmosphere. Thereby, the organic substances (for example, the binderresin, residual solvent, specific plasticizer, various additives)contained in the film forming material layer F2 are decomposed andremoved, and the inorganic particles are molten and sintered. Thesintering temperature which differs according to the melting temperatureof the substrate and the constituent components of the film formingmaterial layer is, for example, 300 to 800° C., preferably 400 to 600°C.

PDP Production Process (Formation of Constituent Element Making Use ofPhotoresist Method)

[0131] The production process of the present invention comprises thesteps of transferring a film forming material layer constituting thetransfer film of the present invention to the surface of a substrate,forming a resist film on the transferred film forming material layer,exposing the resist film to form a resist pattern latent image,developing the resist film to form a resist pattern, etching the filmforming material layer to form a pattern layer corresponding to theresist pattern and baking the pattern layer to form a constituentelement selected from the group consisting of a barrier, electrode,resistor, dielectric layer, phosphor, color filter and black matrix.

[0132] Alternatively, the production process of the present inventioncomprises the steps of forming a laminate film consisting of a resistfilm and a film forming material layer formed of the composition of thepresent invention on a base film in the order named, transferring thelaminate film formed on the base film to the surface of a substrate,exposing the resist film constituting the laminate film to form a resistpattern latent image, developing the resist film to form a resistpattern, etching the film forming material layer to form a pattern layercorresponding to the resist pattern and baking the pattern layer to forma constituent element selected from the group consisting of a barrier,electrode, resistor, dielectric layer, phosphor, color filter and blackmatrix.

[0133] A method of forming “barriers” which are a constituent element ofa PDP on the rear surface of a substrate will be described hereinunder.This method comprises (1) the step of transferring a film formingmaterial layer, (2) the step of forming a resist film, (3) the step ofexposing the resist film, (4) the step of developing the resist film,(5) the step of etching the film forming material layer and (6) the stepof baking a barrier pattern to form barriers on the surface of thesubstrate.

[0134] FIGS. 3 and FIGS. 4 are schematic sectional views showing aseries of steps of forming the barriers. In FIGS. 3 and FIGS. 4,reference numeral 11 denotes a glass substrate on which electrodes 12for generating plasma are arranged at equal intervals and covered with adielectric layer 13 formed on the surface.

[0135] In the present invention, the expression “transferring a filmforming material layer to the surface of a substrate” means not only“transferring the film forming material layer to the surface of theabove glass substrate 11” but also “transferring the film formingmaterial layer to the surface of the above dielectric layer 13”.

[0136] (1) Step of Transferring Film Forming Material Layer

[0137] An example of the step of transferring the film forming materiallayer is given below.

[0138] After the cover film (not shown) of the transfer film is peeledoff, as shown in FIG. 3(b), the transfer film 20 is placed upon thesurface of the dielectric layer 13 in such a manner that the surface ofthe film forming material layer 21 comes into contact with thedielectric layer 13 and press-bonded with a heating roll, and the basefilm 22 is peeled off and removed from the film forming material layer21. Thereby, as shown in FIG. 3(c), the film forming material layer 21is transferred and closely bonded to the surface of the dielectric layer13. Transfer conditions include a heating roll surface temperature of 80to 140° C., a heating roll pressure of 1 to 5 kg/cm² and a heating rollmoving speed of 0.1 to 10.0 m/min. The glass substrate 11 may bepreheated at a temperature of 40 to 100° C., for example.

[0139] (2) Step of Forming Resist Film

[0140] In this step, as shown in FIG. 3(d), the resist film 31 is formedon the surface of the transferred film forming material layer 21. Aresist constituting this resist film 31 may be either a positive resistor a negative resist.

[0141] The resist film 31 can be formed by coating a resist by a screenprinting method, roll coating method, rotation coating method, castcoating method or the like and drying the coating film. The dryingtemperature of the coating film is generally about 60 to 130° C.

[0142] A resist film formed on the base film may be transferred to thesurface of the film forming material layer 21. This method can reducethe number of steps of forming the resist film and makes it possible toobtain a resist film having excellent thickness uniformity, whereby thedevelopment of the resist film and the etching of the film formingmaterial layer are carried out uniformly and the formed barriers becomeuniform in height and shape.

[0143] The resist film 31 has a thickness of 0.1 to 40 μm, preferably0.5 to 20 μm.

[0144] (3) Step of Exposing Resist Film

[0145] In this step, as shown in FIG. 3(e), the surface of the resistfilm 31 formed on the film forming material layer 21 is selectivelyirradiated with (exposed to) radiation such as ultraviolet radiationthrough an exposure mask M to form a resist pattern latent image. In thefigure, MA and MB signify a light transmitting portion and a lightshielding portion formed by the exposure mask M, respectively.

[0146] An irradiation device is not particularly limited and may be anultraviolet irradiation device used for photolithography and an exposuredevice used for the production of semiconductors and liquid crystaldisplay devices.

[0147] (4) Step of Developing Resist Film

[0148] In this step, the exposed resist film is developed to form aresist pattern (latent image).

[0149] As developing conditions, the type, composition and concentrationof a developer, developing time, developing temperature, developingmethod (such as an immersion, rocking, shower, spray or puddling method)and developing device may be suitably selected according to the type ofthe resist film 31.

[0150] A resist pattern 35 (pattern corresponding to the exposure maskM) consisting of resist remaining portions 35A and resist removedportions 35B is formed by this developing step as shown in FIG. 4(f).

[0151] This resist pattern 35 serves as an etching mask in the followingstep (etching step) and the constituent material (photo-cured resist) ofthe resist remaining portions 35A must have a lower dissolution speed inan etching solution than the constituent material of the film formingmaterial layer 21.

[0152] (5) Step of Etching Film Forming Material Layer

[0153] In this step, the film forming material layer is etched to form abarrier pattern layer corresponding to the resist pattern.

[0154] That is, as shown in FIG. 4(g), portions corresponding to theresist removed portions 35B of the resist pattern 35 of the film formingmaterial layer 21 are dissolved in the etching solution and selectivelyremoved. FIG. 4(g) shows that the film forming material layer 21 isbeing etched.

[0155] When etching is further continued, as shown in FIG.4(h),predetermined portions of the film forming material layer 21 arecompletely removed and the dielectric layer 13 is exposed. Thereby, abarrier pattern layer 25 consisting of material layer remaining portions25A and material layer removed portions 25B is formed.

[0156] As etching conditions, the type, composition and concentration ofthe etching solution, etching time, etching temperature, etching method(such as an immersion, rocking, shower, spray or puddling method) andetching device may be suitably selected according to the type of thefilm forming material layer 21.

[0157] The type of the resist film 31 and the type of the film formingmaterial layer 21 are selected such that the same solution as thedeveloper used in the developing step can be used as the etchingsolution in order to carry out the developing step and the etching stepcontinuously, thereby making it possible to improve productionefficiency due to the simplification of the process.

[0158] Preferably, the resist remaining portions 35A constituting theresist pattern 35 are gradually dissolved by etching and completelyremoved when the barrier pattern layer 25 is formed (at the end ofetching). Even when part or all of the resist remaining portions 35Aremain after etching, the resist remaining portions 35A are removed inthe following baking step.

[0159] (6) Step of Baking Barrier Pattern Layer

[0160] In this step, barriers are formed by baking the barrier patternlayer 25. Thereby, the organic substances contained in the materiallayer remaining portions 25A are calcined and barriers are formed,whereby a panel material 50 having barriers 40 formed on the surface ofthe dielectric layer 13 as shown in FIG. 4(i) is obtained. In this panelmaterial 50, spaces partitioned by the barriers 40 (spaces derived fromthe material layer removed portions 25B) serve as plasma working spaces.

[0161] The baking temperature must be a temperature at which the organicsubstances contained in the material layer remaining portions (25A) arecalcined, generally 400 to 600° C. The baking time is generally 10 to 90minutes.

Preferred Embodiment Making Use of Photoresist Method

[0162] The process for forming a PDP in the present invention is notlimited to the process shown in FIGS. 3 and FIGS. 4.

[0163] Other preferred process for forming a constituent element of aPDP comprises the following steps (1) to (3). (1) After a resist film isformed on a base film, the inorganic particle-containing composition ofthe present invention is coated on the surface of the resist film anddried to form a film forming material layer. A roller coater may be usedto form the resist film and the film forming material layer, therebymaking it possible to form a laminate film having excellent thicknessuniformity on the base film.

[0164] (2) The laminate film consisting of the resist film and the filmforming material layer formed on the base film is transferred to thesurface of a substrate. Transfer conditions may be the same as those inthe above “step of transferring film forming material layer”.

[0165] (3) The same operations as described in the above “step ofexposing resist film”, “step of developing resist film”, “step ofetching film forming material layer” and “step of baking barrier patternlayer” are carried out. As described in the foregoing, the developer ofthe resist film and the etching solution of the film forming materiallayer are preferably made the same so that the “step of developingresist film” and the “step of etching film forming material layer” arecarried out continuously.

[0166] Since the film forming material layer and the resist film aretransferred to the surface of the substrate by the above method en bloc,production efficiency can be further improved by the simplification ofthe process.

[0167] The method of forming “barriers” as a constituent element of aPDP has been described above. Electrodes, resistor, dielectric layer,phosphor, color filter and black matrix constituting a PDP can be formedin accordance with this method.

[0168] The following examples are provided for the purpose of furtherillustrating the present invention but are in no way to be taken aslimiting. “Parts” in the following examples means “parts by weight”.

Example 1

[0169] (1) preparation of glass paste composition (inorganicparticle-containing composition):

[0170] The composition of the present invention having a viscosity of4,000 cp was prepared by kneading together 100 parts of a PbO—B₂O₃—SiO₂mixture (softening point of 500° C.) consisting of 70 wt % of leadoxide, 10 wt % of boron oxide and 20 wt % of silicon oxide, 20 parts ofpolybutyl methacrylate as a binder resin (weight average molecularweight of 50,000) as a binder resin, 1 part of a compound represented bythe following formula (a) (propylene glycol monooleate) as a specificplasticizer and 20 part of propylene glycol monomethyl ether as asolvent with a dispersion mixer.

[0171] (2) production and evaluation (flexibility and handlingproperties) of transfer film:

[0172] The composition of the present invention prepared in

[0173] (1) above was coated on a polyethylene terephthalate (PET) basefilm which had been subjected to a release treatment (width of 400 mm,length of 30 m, thickness of 38 μm) using a blade coater and the formedcoating film was dried at 100° C. for 5 minutes to remove the solvent,thereby forming a 50 μm-thick film forming material layer on the basefilm. Thereafter, a PET cover film (width of 400 mm, length of 30 m,thickness of 25 μm) which has been subjected to a release treatment waslaminated on the film forming material layer to produce the transferfilm of the present invention constituted as shown in FIGS. 2.

[0174] The obtained transfer film had suppleness and could be easilyrolled. The film forming material layer had excellent flexibility thatthe surface of the film forming material layer was not cracked even whenthis transfer film was bent.

[0175] The cover film was removed from this transfer film and thetransfer film (laminate consisting of the base film and the film formingmaterial layer) was placed upon a glass substrate without applyingpressure in such a manner that the surface of the film forming materiallayer came into contact with the surface of the glass substrate, andthen the transfer film was removed from the surface of the glasssubstrate. The film forming material layer showed appropriate tackinessto the glass substrate and the transfer film could be removed withoutcausing a cohesive failure in the film forming material layer.Therefore, the transfer film had excellent handling properties.

[0176] (3) Transfer of Film Forming Material Layer

[0177] After the cover film was removed from the transfer film obtainedin (2) above, the transfer film (laminate consisting of the base filmand the film forming material layer) was placed upon a glass substratefor a 20-inch panel in such a manner that the surface of the filmforming material layer came into contact with the surface (bus electrodefixed surface) of the glass substrate and press-bonded with a heatingroll under heating. Press bonding conditions included a heating rollsurface temperature of 110° C., a roll pressure of 3 kg/cm and a heatingroll moving speed of 1 m/min.

[0178] After the end of press-bonding, the base film was peeled off andremoved from the film forming material layer fixed (bonded underheating) to the surface of the glass substrate to complete the transferof the film forming material layer.

[0179] When the base film was peeled off in this transfer step, the filmforming material layer had sufficiently large film strength that acohesive failure did not occur in the film forming material layer.Further, the transferred film forming material layer had excellentadhesion to the surface of the glass substrate.

[0180] (4) Baking of Film Forming Material Layer (Formation ofDielectric Layer)

[0181] The glass substrate having the film forming material layertransferred in (3) above was placed in a kiln and baked at 590C. for 30minutes by elevating the temperature inside the kiln from normaltemperature to 590° C. at a rate of 10° C./min to form an achromatictransparent dielectric layer made of a glass sintered body on thesurface of the glass substrate.

[0182] When the thickness (average thickness and tolerance) of thisdielectric layer was measured, it was in the range of 30 μm±0.4 μm.Thus, the dielectric layer had excellent thickness uniformity.

[0183] When 5 panel materials, each comprising a glass substrate havinga dielectric layer, were produced and the light transmittance of each ofthe formed dielectric layers was measured (measurement wavelength of 600nm), it was 95%. Thus, it was confirmed that all the dielectric layershad excellent transparency.

Example 2

[0184] The composition of the present invention having a viscosity of4,000 cp was prepared in the same manner as in (1) of Example 1 exceptthat the amount of the compound (specific plasticizer) represented bythe above formula (a) was changed to 5 parts and the transfer film ofthe present invention having suppleness was produced in the same manneras in (2) of Example 1 except that the composition was used.

[0185] The obtained transfer film was used for the evaluation offlexibility and handling properties of the film forming material layerin the same manner as in (2) of Example 1. The film forming materiallayer had excellent flexibility that the surface of the film formingmaterial layer was not cracked (flex cracking) when the transfer filmwas bent. The transfer film had excellent handling properties.

[0186] The film forming material layer was transferred in the samemanner as in (3) of Example 1 except that the obtained transfer film wasused. The film forming material layer had sufficiently large filmstrength that a cohesive failure did not occur in the film formingmaterial layer when the base film was removed in this transfer step.Further, the transferred film forming material layer had excellentadhesion to the surface of the glass substrate.

[0187] The glass substrate having the film forming material layertransferred thereto was baked in the same manner as in (4) of Example 1to form an achromatic transparent dielectric layer made of a glasssintered body on the surface of the glass substrate.

[0188] When the thickness of the dielectric layer (average filmthickness and tolerance) was measured, it was in the range of 30 μm±0.5μm. Thus, the dielectric layer had excellent thickness uniformity.

[0189] When 5 panel materials, each comprising a glass substrate havinga dielectric layer, were produced and the light transmittance of each ofthe formed dielectric layers was measured (measurement wavelength of 600nm), it was 95%. Thus, it was confirmed that all the dielectric layershad excellent transparency.

Example 3

[0190] The composition of the present invention having a viscosity of3,500 cp was prepared in the same manner as in (1) of Example 1 exceptthat 5 parts of a compound represented by the following formula (b)(di-2-ethylhexyl azelate) was used in place of the compound representedby the above formula (a) and the transfer film of the present inventionhaving suppleness was produced in the same manner as in (2) of Example 1except that the composition was used.

[0191] The obtained transfer film was used for the evaluation offlexibility and handling properties of the film forming material layerin the same manner as in (2) of Example 1. The film forming materiallayer had excellent flexibility that the surface of the film formingmaterial layer was not cracked (flex cracking) when the transfer filmwas bent. The transfer film had excellent handling properties.

[0192] The film forming material layer was transferred in the samemanner as in (3) of Example 1 except that the obtained transfer film wasused. The film forming material layer had sufficiently large filmstrength that a cohesive failure did not occur in the film formingmaterial layer when the base film was removed in this transfer step.Further, the transferred film forming material layer had excellentadhesion to the surface of the glass substrate.

[0193] The glass substrate having the film forming material layertransferred thereto was baked in the same manner as in (4) of Example 1to form an achromatic transparent dielectric layer made of a glasssintered body on the surface of the glass substrate.

[0194] When the thickness of the dielectric layer (average filmthickness and tolerance) was measured, it was in the range of 30 μm±0.5μm. Thus, the dielectric layer had excellent thickness uniformity.

[0195] When 5 panel materials, each comprising a glass substrate havinga dielectric layer, were produced and the light transmittance of each ofthe formed dielectric layers was measured (measurement wavelength of 600nm), it was 95%. Thus, it was confirmed that all the dielectric layershad excellent transparency.

COMPARATIVE EXAMPLE 1

[0196] A composition for comparison having a viscosity of 3,000 cp wasprepared in the same manner as in (1) of Example 1 except that aspecific plasticizer was not used and a transfer film for comparison wasproduced in the same manner as in (2) of Example 1 except that thecomposition was used.

[0197] The obtained transfer film was inferior in suppleness anddifficult to be rolled. When the transfer film was bent, the surface ofthe film forming material layer was markedly cracked (flex cracking).Thus, the film forming material layer was inferior in flexibility.

[0198] The film forming material layer was transferred in the samemanner as in (3) of Example 1 except that the obtained transfer film wasused and further the glass substrate having the film forming materiallayer transferred thereto was baked in the same manner as in (4) ofExample 1 to form an achromatic dielectric layer made of a glasssintered body on the surface of the glass substrate.

[0199] When the thickness of the dielectric layer (average filmthickness and tolerance) was measured, it was in the range of 30 μm±0.5μm.

REFERENCE EXAMPLE 1

[0200] A composition having a viscosity of 4,000 cp was prepared in thesame manner as in (1) of Example 1 except that the amount of thecompound (specific plasticizer) represented by the above formula (a) waschanged to 0.1 part and a transfer film was produced in the same manneras in (2) of Example 1 except that the composition was used.

[0201] The obtained transfer film was slightly inferior in supplenessand slightly difficult to be rolled. When the transfer film was bent,the surface of the film forming material layer was slightly cracked(flex cracking).

[0202] The film forming material layer was transferred in the samemanner as in (3) of Example 1 except that the obtained transfer film wasused and further the glass substrate having the film forming materiallayer transferred thereto was baked in the same manner as in (4) ofExample 1 to form an achromatic dielectric layer made of a glasssintered body on the surface of the glass substrate.

[0203] When the thickness of the dielectric layer (average filmthickness and tolerance) was measured, it was in the range of 30 μm±0.5μm.

REFERENCE EXAMPLE 2

[0204] A composition having a viscosity of 4,500 cp was prepared in thesame manner as in (1) of Example 1 except that the amount of thecompound (specific plasticizer) represented by the above formula (a) waschanged to 20 parts and a transfer film was produced in the same manneras in (2) of Example 1 except that the composition was used.

[0205] The obtained transfer film was used for the evaluation offlexibility of the film forming material layer in the same manner as in(2) of Example 1. The film forming material layer had excellentflexibility that the surface of the film forming material layer was notcracked (flex cracking) even when the transfer film was bent.

[0206] The cover film was removed from the transfer film, the transferfilm (laminate consisting of the base film and the film forming materiallayer) was placed upon a glass substrate without applying pressure tothe transfer film in such a manner that the surface of the film formingmaterial layer came into contact with the surface of the glasssubstrate, and then the transfer film was removed from the surface ofthe glass substrate. At this point, the tackiness of the film formingmaterial layer to the glass substrate was too large and hence, part ofthe film forming material layer was adhered to the glass substrate.Thus, the transfer film was inferior in handling properties.

[0207] The film forming material layer was transferred in the samemanner as in (3) of Example 1 except that the obtained transfer film wasused and further the glass substrate having the film forming materiallayer transferred thereto was baked in the same manner as in (4) ofExample 1 to form an achromatic dielectric layer made of a glasssintered body on the surface of the glass substrate.

[0208] When the thickness of the dielectric layer (average filmthickness and tolerance) was measured, it was in the range of 30 μm±0.5μm.

EXAMPLE 4

[0209] (1) Preparation of Conductive Pasty Composition (InorganicParticle-containing Composition)

[0210] The composition of the present invention for forming electrodeswas prepared by kneading together 100 parts of silver powders asinorganic particles, 40 parts of an n-butyl methacrylate/methacrylicacid (weight ratio of 70/30) copolymer (weight average molecular weightof 70,000) as a binder resin, 5 parts of a compound represented by theabove formula (a) (propylene glycol monooleate) as a specificplasticizer and 20 part of propylene glycol monomethyl ether as asolvent with a dispersion mixer.

[0211] (2) Preparation of Resist Composition

[0212] A pasty alkali development radiation sensitive resist compositionwas prepared by kneading together 50 parts of an n-butylmethacrylate/methacrylic acid (weight ratio of 85/15) copolymer (weightaverage molecular weight of 50,000) as an alkali-soluble resin, 40 partsof pentaerythritol tetraacrylate as a polyfunctional monomer (radiationsensitive component), 5 parts of2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one as aphotopolymerization initiator (radiation sensitive component) and 150parts of ethyl 3-ethoxypropionic acid as a solvent.

[0213] (3) Production and Evaluation (Flexibility and HandlingProperties) of Transfer Film

[0214] The resist composition obtained in (2) above was coated on thesurface of the same base film as used in Example 1 with a blade coaterand the formed coating film was dried at 100° C. for 5 minutes to removethe solvent, thereby producing a 5 μm-thick resist film on the basefilm. Thereafter, the composition for forming electrodes obtained in (1)above was coated on the surface of the resist film and dried to form a20 μm-thick film forming material layer. A cover film was then formed onthe film forming material layer in the same manner as in Example 1 toproduce the transfer film of the present invention.

[0215] The obtained transfer film was used for the evaluation offlexibility and handling properties of the film forming material layerin the same manner as in (2) of Example 1. The film forming materiallayer had excellent flexibility that the surface of the film formingmaterial layer was not cracked (flex cracking) even when the transferfilm was bent. This transfer film had excellent handling properties.

[0216] (4) Transfer of Film Forming Material Layer

[0217] After the cover film was removed from the transfer film obtainedin (3) above, the transfer film was placed upon a glass substrate for a6-inch panel in such a manner that the surface of the film formingmaterial layer came into contact with the surface of the glass substrateand then press-bonded by a heating roll under heating. Press-bondingconditions included a heating roll surface temperature of 120° C., aroll pressure of 4 kg/cm² and a heating roll moving speed of 0.5 m/min.

[0218] After the end of press-bonding under heating, the base film waspeeled off and removed from the resist film to complete the transfer ofthe laminate film consisting of the film forming material layer and theresist film.

[0219] When the base film was peeled off in this transfer step, the filmforming material layer had sufficiently large film strength that acohesive failure did not occur in the film forming material layer.Further, the transferred film forming material layer had excellentadhesion to the surface of the glass substrate.

[0220] (5) Exposure of Resist Film

[0221] The resist film was exposed to an i-ray (ultraviolet light havinga wavelength of 365 nm) from an ultra-high pressure mercury lamp throughan exposure mask (50 μm-wide stripe pattern). The amount of exposure was400 mJ/cm².

[0222] (6) Development of Resist Film and Etching of Film FormingMaterial Layer

[0223] The exposed resist film was developed by a shower method using a0.2 wt % potassium hydroxide aqueous solution (25° C.) as a developerfor 20 seconds. Thereafter, the resist film was washed with ultra-purewater to remove uncured resist portions not exposed to ultravioletradiation so as to form a resist pattern.

[0224] Right after the above step, the film forming material layer wasetched by a shower method using a 0.2 wt % potassium hydroxide aqueoussolution (25° C.) as an etching solution for 2 minutes. Thereafter, thefilm forming material layer was washed with ultra-pure water and dried.Thereby, a film forming material layer pattern consisting of materiallayer remaining portions and material layer removed portions was formed.

[0225] (7) Baking of Film Forming Material Layer

[0226] The glass substrate having the film forming material layerpattern formed thereon was baked in a kiln at 600° C. for 30 minutes.Thereby, electrodes were formed on the surface of the glass substrate.

[0227] When the section of each of the electrodes was observed through ascanning electron microscope to measure the width at the bottom andheight of the section, the width at the bottom was 50 μm±2 μm and theheight was 10 μm±1 μm. Thus, the dimensional accuracy was very high.

[0228] The composition of the present invention provides the followingeffects:

[0229] (1) it can suitably form a constituent element (for example, abarrier, electrode, resistor, dielectric layer, phosphor, color filteror black matrix) of a PDP;

[0230] (2) it can suitably form a glass sintered body having high lighttransmittance (for example, a dielectric layer or barrier constituting aPDP);

[0231] (3) it can produce a transfer film comprising a film formingmaterial layer having excellent flexibility; and

[0232] (4) it can produce a transfer film comprising a film formingmaterial layer having excellent transferability of a film formingmaterial layer (heat adhesion to a substrate).

[0233] The transfer film of the present invention provides the followingeffects:

[0234] (1) it can form a constituent element (especially a dielectriclayer) of a PDP efficiently;

[0235] (2) it comprises a film forming material layer having excellentflexibility and is free from flex cracking on the surface of the filmforming material layer;

[0236] (3) it has excellent suppleness and can be easily rolled;

[0237] (4) it comprises a film forming material layer which exhibitsappropriate tackiness and has excellent handling properties; and

[0238] (5) it has excellent transferability of the film forming materiallayer (heat adhesion to a substrate).

[0239] The production process of the present invention provides thefollowing effects:

[0240] (1) it can form a constituent element (for example, a barrier,electrode, resistor, dielectric layer, phosphor, color filter or blackmatrix) of a pdp efficiently;

[0241] (2) it can form a pdp having the high position accuracy of aconstituent element efficiently;

[0242] (3) it can form a dielectric layer having large thicknessefficiently;

[0243] (4) it can form a dielectric layer required for a large-sizedpanel efficiently; and

[0244] (5) it can produce a pdp comprising a dielectric layer havingexcellent uniformity and surface flatness efficiently.

What is claimed is:
 1. An inorganic particle-containing compositioncomprising: (A) inorganic particles; (B) a binder resin; and (C) atleast one plasticizer selected from the group consisting of compoundsrepresented by the following formula (1):R¹O—R²_(m)OOC—(CH₂_(n)COOR³—O_(m)R⁴  (1) wherein R¹ and R⁴ are thesame or different alkyl groups having 1 to 30 carbon atoms or alkenylgroups, R² and R³ are the same or different alkylene groups having 1 to30 carbon atoms or alkenylene groups, m is an integer of 0 to 5, and nis an integer of 1 to 10, and compounds represented by the followingformula (2):

wherein R⁵ is an alkyl group having 1 to 30 carbon atoms or alkenylgroup.
 2. The inorganic particle-containing composition of claim 1,wherein the inorganic particles (A) are at least one electricallyco-aductive particles pa selected from the group consisting of Ag, Au,Al, Ni, Ag—Pd alloy, Cu and Cr.
 3. The inorganic particle-containingcomposition of claim 1, wherein the binder resin (B) is an acrylic resincontaining a polymer unit derived from a compound represented by thefollowing formula (3):

A transfer film and a plasma display panel production process using thecomposition are also described. wherein R⁶ is a hydrogen atom or methylgroup, and R⁷ is a monovalent organic group.
 4. The inorganicparticle-containing composition of claim 1, wherein the binder resin isat least one member selected from the group consisting of a homopolymerof a (meth)acrylate compound represented by the above formula (3), acopolymer of two or more (meth)acrylate compounds represented by theabove formula (3) and a copolymer of a (meth) acrylate compoundrepresented by the above formula (3) and other copolymerizable monomer.5. The inorganic particle-containing composition of claim 1 whichfurther contains a silane coupling agent represented by the followingformula (4):

wherein p is an integer of 3 to 20, m is an integer of 1 to 3, n is aninteger of 1 to 3, and a is an integer of 1 to
 3. 6. The inorganicparticle-containing composition of claim 1 which contains 5 to 80 partsby weight of the binder resin (B) and 0.1 to 20 parts by weight of theplasticizer (C) based on 100 parts by weight of the inorganic particles(A).
 7. A transfer film comprising a base film and a film formingmaterial layer formed of the inorganic particle-containing compositionof claim 1 on the base film.
 8. A plasma display panel productionprocess comprising the steps of: transferring the film forming materiallayer of the transfer film of claim 7 to the surface of a substrate; andbaking the transferred film forming material layer to form an dielectriclayer on the substrate.
 9. A plasma display panel production processcomprising the steps of: transferring a film forming material layerformed of the inorganic particle-containing composition of claim 1 tothe surface of a substrate; forming a resist film on the transferredfilm forming material layer; exposing the resist film to form a resistpattern latent image; developing the resist film to form a resistpattern; etching the film forming material layer to form a pattern layercorresponding to the resist pattern; and baking the pattern layer toform a constituent element selected from the group consisting of abarrier, electrode, resistor, dielectric layer, phosphor, color filterand black matrix.
 10. A plasma display panel production processcomprising the steps of: transferring a film forming material layerformed of the inorganic particle-containing composition of claim 2 tothe surface of a substrate; forming a resist film on the transferredfilm forming material layer; exposing the resist film to form a resistpattern latent image; developing the resist film to form a resistpattern; etching the film forming material layer to form a pattern layercorresponding to the resist pattern; and baking the pattern layer toform electrodes.
 11. A plasma display panel production processcomprising the steps of: forming a laminate film consisting of a resistfilm and a film forming material layer formed of the inorganicparticle-containing composition of claim 1 on a base film in the ordernamed; transferring the laminate film formed on the base film to thesurface of a substrate; exposing the resist film constituting thelaminate film to form a resist pattern latent image; developing theresist film to form a resist pattern; etching the film forming materiallayer to form a pattern layer corresponding to the resist pattern; andbaking the pattern layer to form a constituent element selected from thegroup consisting of a barrier, electrode, resistor, dielectric layer,phosphor, color filter and black matrix.
 12. A plasma display panelproduction process comprising the steps of: forming a laminate filmconsisting of a resist film and a film forming material layer formed ofthe inorganic particle-containing composition of claim 2 on a base filmin the order named; transferring the laminate film formed on the basefilm to the surface of a substrate; exposing the resist filmconstituting the laminate film to form a resist pattern latent image;developing the resist film to form a resist pattern; etching the filmforming material layer to form a pattern layer corresponding to theresist pattern; and baking the pattern layer to form electrodes.